Plating metal fasteners



Nov. 9', 1943. P. c. wooTERs PLATING METAL FASTENERS Filed Oct. 27, 1959 me @www om NR mm.

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Patented Nov. 9, 1943 PLATING METAL FASTENERS Percival C. Wouters, Meadville, Pa., assigner to Talon, Inc., a corporation of Pennsylvania Application October 27, 1939, Serial No. 301,613

3 Claims.

This invention relates to the plating, coloring and otherwise coating of slide fasteners by electrolytic means wherein the stringers comprise suitable supporting tapes having thereon interengageable metal fastener members or scoops.

It is an object of this invention to provide a method to obtain a continuous electrical contact for electrolytically plating, coloring or otherwise coating the interengageable scoops or fastener members of slide fasteners after their attachment to stringer tapes. This method employs the use of a metallic foil of such thickness and size as to meet whatever current carrying requirements may be necessary for any particular electrolytic treatment. The use of' this foil provides a distinctly separate'and external means of furnishing It is a further object of this invention to provide a method wherein uniformity of plating, co1- oring or otherwise coating -of fastener members or scoops is secured because of attainment of uniform and positive electrical contact between the respective fastener members or scoops in fastener stringers and between the respective fastener members or scoops and the electrolyte or solution in which the plating is carried out.

It is a further object of this invention to provide such a method which embodies ultimate economy because of the utilization of low cost metal foil to provide the above described uniform electrical connection between the respective fastener members or scoops and the electrolyte or solution in which the electrolytic process is carried out.

It is a further object of this invention to provide such a method wherein the provision of the electrical connection between the fastener members or scoops and the electrolyte is achieved through th utilization of the above described low cost metal foil without, in any way, reinforcing or( modifying the scoop supporting Stringer tapes or impairing the flexibility thereof.

It is a further object of this invention to provide such a method wherein the relationship between the Stringer tape and attached fastener members or Scoops is unalfected and undisturbed and wherein the necessity for the application of overstretching stress to the Stringer tapes is totally avoided.

It is a further object of this invention to provide a method particularly adapted to anodized coating and subsequent dye coloring of slide fastener scoops or fastener members and wherein it is possible to secure complete uniformity of coloring of the respective fastener members or scoops in the fastener stringers.

These and other objects of the invention will appear from the following description taken in connection with the accompanying drawing.

In the drawing:

Fig. 1 is a fragmentary view illustrating, in plan, the pulling up between cooperating slide fastener stringers of the metal foil utilized according to this invention, which metal foil is guided by the foil guiding slider tool shown in section, as indicated by the line l-l in Fig. 2;

Fig. 2 is a section taken substantially on the line 2 2 of Fig. l;

Fig. 3 is a View, similar to Fig. 2, of a modied form of foil guiding slidertool;

Fig. 4 is a view, similar to Fig. 2, but illustrating a multiple foil guiding slider tool constituting a second modification of the foil guiding slider tool illustrated in Figs. 1 and 2;

Fig. 5 is an enlarged fragmentary detail of Fig. l with fastener scoops and interengaged metal foil shown in section;

Fig. 6 is a fragmentary plan View showing a metal foil strip pulled up between cooperating gap spaced stringers of fastener chain according to this invention;

Fig. '7 is a fragmentary, diagrammatic view illustrating the application of the principles of this invention to a fastener coloring process involving anodio oxidation; and Y Fig. 8 is a View, similar to Fig. 7, but illustrating the application of the principles of this invention in treating a slide fastener by electrolytic color plating process.

Formerly, in order to secure desired uniformity of plating, color plating, and particularly anodic coating in slide fasteners, it has generally been found necessary either to treat the fastener members or scoops electrolytically prior to their attachment to the reinforced edges of slide fastener Stringer tapes or to incorporate in the stringers, in association with the tapes and attached fastener members or scoops, means providing electrical contact between the fastener members or scoops of the stringers. These practices were followed in order to secure uniformity of plating, coloring or coating and subsequent color between to contact with, various mechanisms and tools required, subsequently,'to secure them to the stringer tapes. This contact of these surfaces with the mechanisms and tools was accompanied, necessarily, by undesirable surface defacement.

While some attempts have been .made electronascose A y It is extremely important that the current carrying capacity of the conducting medium be high enough for the electrolytic process involved and by the use of this method. the necessary capacity is-readily secured by varying the thickness and size of foil to meet a particular application., The depth of the anodically formed coating .depends mainly upon (a) the time through which the scoop surfaces aresubiected to anodic oxidation, and also (b) the current to which the respective scoops are subjected during anodic oxidation. It j lytically to treat the scoops or fastener members of slide fasteners by use of separate electrical contact providing means after their attachment to stringer tapes, the attempted methods-have not been completely satisfactory because of the dimculty of securing uniform electrical connection between the adjacent scoops or fastener members and between the scoops or fastener members and the electrolyte or plating solution.

' Another method incorporating the application of stressy to the stringer tapes in fasteners having the scoops or fastener members thereof engaged has, perhaps, been chief among the many formerly attempted methods, but such practice is accompanied by extremely undesirable* overstressing of the stringer tapes whereby the relationship of the respective scoops or vfastener members on the stringer tapes ismodiiied in such manner as substantially to impair the utility of the stringers.

According to this invention, the above objections to prior known methods are obviated by the use of suitable metal foil which is pulled up between cooperating stringers of a slide fastener prior to surface treatment thereof. The metal.

foil provides substantially uniform electrical connection between the respective scoops or fastener members in the stringers of the fastener. This practice is applicable tu'various known electrolytic plating processes and isparticularly adapted to anodic oxidation of metals wherein it is of prime importance that uniform anodizing of the scoops or fastener members should be secured.

In one such process, the following steps are carried out:

is, therefore, of prime importance that the cur-A rent, which has formerly been the variable factor, be made uniform and invariable as between the respective scoops ofthe fastener in order that complete uniformity of color be secured in the fastener as a unit. By the use of metal foil asa connecting medium, common uniform electrical connection is secured between the respecr tive scoops of fasteners, which connection is unaffected by the formation of anodic coatings, oxide color film or metallic plate.

The principles of this invention are also ap'- plicable to that method of electro-color plating wherein the scoops, which are formed of suitable metal or alloy, are subjectedto an electrolytic treatment which forms a cuprous oxidenlm. These thin films cause light interference which produces a surface coloring having spectral properties. In this process, the following steps are carried out:

1. The metal scoops of the fastener are cleaned, in suitable manner, to remove dirt and foreign matter from the scoop surfaces.

2. 'Ihe scoops are electro-color plated by elec trolytic means while immersed in .a suitable electrolyte of which one is comprised mainly of copper sulphate. Rochelle salts, etc., which bath contains an anode of copper. The scoops, which I are electrically connected by a strip of` copper foil, according to this'4 invention,v form the cathode. Extremely low voltages and currents are used, the voltage being preferably 11,4;` volts or less and the current being between l0 and 50 1. The metal scoops ofy an aluminum fastener 3. The anodized or anodically oxidized scoops are neutralized by rinsing with a suitable base, such as dilute ammonium hydroxide; and then thoroughly rinsed in clear cold water several times.

4. The rinsed fastener is immersed in a dye bath of the desired color and at the definite temperature and pH necessary for dyeing the anodized aluminum surfaces.

5. The color is sealed by treatment with nickel acetate, preferably by boiling the dyed fastener for approximately five minutes in nickel acetate solution.

In the above process, considerable difficulty has been encountered in step No. 2 due to the production, in this step, of non-unlform anodic coat milliamperes. The thickness of the iilm depends mainly, of course, upon the time of the plating operation and also upon the current. Where such low current values are used, it is of extreme importance that substantially perfect electrical connection be secured between the respective scoops of the fastener in order to secure uniiiU on the respective aluminum scoops of the coat, it is of extreme importance that the anodic coat formed on the scoop surfaces be uniform.

formity of film thickness through the fastener. The thickness of the nlm controls the spectral effects produced thereby, and any non-uniformity in the iridescent finish provided by this process.

3. The above electrical plating step is preferably followed by a lacquering step wherein a coating of clear lacquer is applied to the electro-color plated surfaces to preserve the finish. This, of course, has some slight effect upon the iridescent finish produced, but as the depth of the lacquer can be readily, carefully, controlled.. then the depth of the plating film is controlled accordinsly. the, uniformity of film thickness being achieved by the use of metal foil to provide sub-v stantially perfect electrical contact between the respective scoops of the fastener during the elec.- trolytic treatment described above.

The principles of this invention are applicable. also, as stated above, to all common plating processes wherein, by an electrolytic process, a fresh metal coating is deposited on the existing metal #C0098 of the fastener. Suitable metal foil is used. according to the principles of this inven- 'll tion. to secure substantially perfect electrical contact between the respective scoops of the fastener, totally unaffected by deposit of plate. The current flow is uniform throughout the fastener and the thickness of the plating or metal nlm is also uniform throughout the fastener. Where such uniformity is secured, it is possible to secure complete coverage of the exposed scoop surfaces with a metal film of any desired slight uniform thickness, thus achieving a substantial economy of plating material.

From the above, it will clearly appear that the use of suitable metal foil, according to the principles of this invention, to secure uniform current flow in electrical plating, color plating, or anodic coating processes makes possible theelectrolytic treatment of scoops or fastener members of slide fasteners after their attachment to the supporting fastener stringer tapes, which treatment was hitherto accomplished prior to the attachent of the scoops or fastener members to the supporting stringer tapes of the fastener, or by modification of the Stringer tapes by imbedding current carrying means, such as wires therein. This latter procedure undesirably increased the rigidity, and reduced theexibility, of the Stringer tapes accordingly as the current carrying capacity of the wire and scoops was increased. This was extremely undesirable in many cases, and in particular where the fasteners were of the smaller slzes.

As illustrative of the principles of this invention, I have shown, and describe hereinafter, the use of aluminum foil pulled up between aluminum Scoops or fastener members of a slide fastener to provide satisfactory uniform electrical connection between the respective scoops or fastener members of the fastener and between these scoops or fastener members and the electrolytic bath or solution in an anodic oxidation process.

I have also shown, and described hereinafter, the manner in which other metal foils are used with fastener members of other metals or alloys wherein, in the electrolytic processes. the cathode is formed by the scoops or fastener members and the electrically conducting metal strip pulled up therebetween.

As shown in the drawing, the slide fastener stringers, generally designated ID, comprise tapes Ii, suitably reinforced at one edge l2 and having secured to this reinforced edge I2 in suitable spaced relationship. metallic scoops or fastener members I 4. These scoop; or fastener members I4, as shown in Fig. 5. have the head portions thereof formed with a projection Ida at one side and a pocket or socket Mb at the other side in order that they may be interengaged as shown. The opposite end portion or leg I4 is of bifurcated form and is clamped over the reinforced edge I2 in known manner. *1

The stringers may be provided with gap spaces Illa as shown in Figs. 6 and '7. or the series of metal, scoops or fastener members on tape. known as chainf may be uninterrupted or continuous, there being no gap spacing provided in the stringers. In order that uniform electrical connection shall be provided between the scoops or fastener members of a fastener. a strip ofmetal foil I ls pulled up between the scoops or fastener members I4 of the complementary fastener stringers III when they are connected, prior to being subjected to an anodizing or other plating step as shown in Figs. l and 5to 8.

In order that this pulling up of the metal foil rportion Mc of each scoop or fastener member y strip I5 between the complementary stringers of a slide fastener may be accomplished with utmost convenience, I have provided a new and improved fou' guiding Suder wel which is either of the single form illustrated in Figs. 2 and 3 and therein generally designated I6 and ISa respectively,

or it may be of multiple form as shown in Fig. 4, wherein it is generally designated I6b.

In the single form illustrated in'Figs. l and 2, the foil guiding slider tool is of the same general form as a conventional slide fastener slider save for the provision of a longitudinal foil strip guiding slot in the wedge or diamond thereof. y In detail, the tool illustrated in Figs. l and 2 comprises a pair of similar wings II and I8 provided in conventional manner with marginal side flanges and connected at their upper ends by a wedge 20 secured between the wings I 'I and I8. This wedge 20 is centrally provided with a longitudinal strip guide slot 2|. The strip guide slot 2| is preferably wider and thicker than the lfoil strip I5 which is desired to be pulled up between the cooperating fastener members or scoops I4 and the complementary stringers I0 in order to provide adequate clearance as shown in Figs, 1 and 2.

In order to pullup a metal foil strip between the cooperating stringers I0 of a slide fastener, it is merely necessary to dispose the fastener members It at the lower ends of the stringers I0 into the channel formed between the Wings I'I and I8',

in the tool I6 and to place a foil strip I5 between these scoops or fastener members III prior to their engagement. Thestrip I5, of course, projects upwardly through the strip guide slot 2| in the wedge 20. The-strip guiding slider tool .I6 is then pulled upwardly with respect to the stringers I0 and foil strip I5, or stringers with foil initially engaged are pulled down with respect to the strip guiding slider tool to secure the strip I5 in interlocking relationship between cooperating Ifastener members or scoops I4 as shown in Fig. 1.

The foil strip I5 is continuous, and for this reason, continuous electrical connection is provided by the foil strip I5 from one end of the fastener strip to the other end thereof, irrespective of the existence of gap spacing Illa in the respective stringers II). y

In order that substantial electrical connection of slight resistance be provided between the respective fastener members or scoops, it is preferable in many cases that the strip I5 extend substantially beyond the zone of contact with the scoops at one side, or, more preferably, at both sides. This is accomplished by the use of a strip guiding slider tool Ilia of the modified form shown in Fig. 3 of the drawing. In this form, the tool is of the general form of that construction illustrated in Figs. 1 and 2 save for the extension of the channel formed by the strip guide slot 2 I substantially beyond the scoops at each side.

This is accomplished by providing wings I Ia and I8a, which are similar to the above described wings Hand I8 save for the provision of integrally formed longitudinal channels IIc and I8c respectively which communicate with the sides of the slot in the wedge 20 to form a strip guide slot 21a, substantially wider than the thickness of the Wedge 20 and capable, therefore, of accommodating a stripI 5 of width substantially greater than the thickness ofthe scoops I4 as shown in Fig. 3.

While it is, perhaps, most preferable that the extension of` the strip beyond the scoops take place at both sides, nevertheless, either one of the channels llc or itc may be omitted without substantial impairment of the efficiency of electrical connection. l

The degree of slot extension thus provided may,

of course, be varied as desired by variation of the s superposed and united. The slots extending through the respective wedges 2l communicate with one another to form a single strip guide slot 2lb accommodating a strip Il of such width as to be capable of being pulled up simultaneously between the scoops Il of a plurality of pairs of fastener stringers Il as shown in Fig. 4.

The end wings I1 and I8 are preferably of the form shown in Figs. 1 and 2 while the intermediate wings, designated I9, are provided with marginal side flanges at both sides. The number of units in this multiple strip guiding tool may, of course, be varied as desired.

In the use of the tool ith, the above described procedure followed in pulling up the strip Il between stringers Il with the tool Il and Ita is modified only in that a plurality of pairs of stringers I0, in superposed relation, are arranged in the channels between the wings of the multiple strip guiding slider tool and a single wide strip II of metal foil extending through the slot 2lb` is'35 placed between the scoops I4 at the lower ends of the stringers I0 before they are engaged, during pulling up, by the multiple strip guiding slider tool Ib.

A substantial advantage of the use of metal foil to provide conducting connection between the scoops Il of the fastener stringers during anodizing resides in the ability of the foil closely to engage the irregular surfaces of the head portions of the scoops. Such close contact is achieved that 4s entry of the electrolyte between the strip and engaged surfaces of the scoops is prevented to such degree as to prevent. therebetween, the'formation of any coat which would impair the electrical connection due to its non-conducting nature such as the oxide or hydroxide coating formed in aluminum anodizing, as illustrated in Fig. '1.

In Fig. 7, which is illustrative of the anodic oxidation of aluminum method first describedN above, the plating tank, designated 22, is of suitable non-conducting material. An electrical conducting bracket 22 is attached thereto, at the top, in such manner as to` extend below thesurface of the electrolyte 2l therein. A suitable electrolyte for this purpose is a 10% l'solution acid.

The positive wire 26 of the plating circuit is connected to the bracket 2,3 by means of the terminal 25. 'I'he anode 21 which comprises complementary stringers il having pulled uptherebetween a strip I5 of aluminum foil, is supported by the bracket 22 to which it is electrically connected by winding of the tape II over the bracket 23 to which it is secured by suitable means, such as spring clamp 28. Also secured to the tank 22 is a conducting bracket 29 having the lead cathode 20 secured thereto andimmersed in the electrolyte 24.

The negative wire of theelectroplating circuit is connected to the conducting bracket 2l 7s bymeansoftheterminaln. Whencurrentof suitable voltage and is passed through the plating circuit which thus inciudesthe anode. y 21, electrolyte 2l and cathode, for a suitable length of time, aluminum oxide orhydroxide coating is form onthe surface of the scoop! I4 which, with the strip Il. form the anode 21: and for the reason pointed out above,` this coating is uniform.

In Fig. 8, which is illustrative of the second of the above described methods, the arrangement isthesameasthatillustratedinlimlsavethat the cathode 2l is formed by the stringers II-and pulled up strip il. which strip is of copper. The bracket 2l supports the copper anode 21, and the positive wire 2l is connected tothe bracket 2l while the negative wire Il is connected to the bracket 2l by the terminal 2l. The electrolyte.

24 is comprised of a suitable solution, such as one constituted mainly of copper sulphate, Rochelle salts, etc., and the plating current is preferably from l0 to 50 milliamperes at orbelow .1% volts.

Passage of current through the circuit including the copper anode 21, the electrolyte 2l and the cathode SII (formed by the stringers and pulled up copper strip) deposits a thin ouvrons oxide nlm which causes light interference and produces surface coloring having spectral properties. Because of the uniformity of electrical connection and consequent uniformity of film thickness. the color is uniform throughout the fastener.

From the above description it will clearly appear that the field of applicationof this invention is of wide scope, that it embodies economy and efficiency to a high degree and that the application of the principles thereof to the various methods of electrolytic plating, coloring or otherwise coating of slide fasteners with metallic fastener members or scoops constitutes a substantial and meritorious advance in the art.

It is, of course, to be understood that' the above described structure is merely illustrative and in no wise limiting and that I desire to comprehend within my invention all modifications included within the scope of the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by letters Patent is: Y v

`1. In a method of electrolytic surfacetreatment of fastener members of slide fasteners including nonconducting stringer tapes with spaced interengageable metallic fastener members thereon, pulling up between the fastener members-of a pair of tapes a flexible conducting foil strip, immersing the amembled stringers and strip in the electrolytic bath of an .electrolytic treatment apparatus, attaching the foil f strip to a terminal of the apparatus to forman of so electrode of the electrolytic treatment apparatus, and passing 'current through the apparatus to secure surface treatment of the fastener members uniformly electrically connected by the conducting strip.

` 2. In a method of anodic surface treatment of fastener members of slide fasteners including nonconducting stringer tapes with spaced interengageable aluminum fastener members thereon,

pulling up between the fastener members of a pair of tapes a exible conducting aluminum foil strip, immersing the assembled' stringers and aluminum foil strip in the electrolytic bath of an electrolytic treatment apparatus, attaching the foil strip to the anode terminal of the apparatus to form the anode of the electrolytic treatment apparatus, and passing current through the apparatus to secure anodic surface treatment of the fastener members uniformly electrically connected by the foil strip.

3. In a method of electrolytic surface plating of fastener members of slide fasteners including -nonconducting Stringer tapes with spaced interengageable metallic fastener members thereon, pulling up between the fastener members of a pair of 'tapes a flexible conducting foil strip, im-

mersing the assembled stringers and foil strip in the electrolytic bath of an electrolytic treatment apparatus, attaching the foil strip to the cathode terminal of the apparatus to form the cathode of the electrolytic treatment apparatus, and passing current through the apparatus to secure surface plating of the fastener members uniformly electrically connected by the foil strip.

PERCIVAL C. WooTERs. 

